Fuel mixture system and assembly

ABSTRACT

A system and attendant structural assembly operative to establish a coordinated mixture of gaseous and distillate fuels for an engine including an electronic control unit (ECU) operative to monitor predetermined engine data determinative of engine fuel requirements and structured to regulate ratios of the gaseous and distillate fuel of an operative fuel mixture for the engine. The system and assembly includes at least one mixing assembly comprising an integrated throttle body and air gas mixer directly connected to one another, wherein the throttle body is disposed in fluid communication with a pressurized gaseous fuel supply and the air gas mixer is disposed in fluid communication with a flow of intake air to a combustion section of the engine. In use, the throttle body is structured to direct a variable gaseous fuel flow directly to the air gas mixer for dispensing into the intake air flow to the combustion section.

CLAIM OF PRIORITY

The present application is a continuation-in-part application ofpreviously filed, now pending application having Ser. No. 13/947,410,filed on Jul. 22, 2013.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is directed to a system and attendant apparatus operativeto establish a variable operative fuel mixture for powering a stationaryengine or generator, as well as a vehicle engine. The operative fuelmixture may comprise a varying ratio of both a gaseous fuel, such asnatural gas, and a distillate fuel, such as diesel. The ratio of gaseousand distillate fuel is dependent, at least in part, on a plurality ofoperating characteristics of the engine, which are monitored by anelectronic control unit (ECU). The system is adaptable for determiningan efficient and effective operative fuel mixture due at least partiallyto the inclusion of one or more mixing assemblies each comprising andintegrated throttle body and air-gas mixer.

2. Description of the Related Art

Typically large, stationary engines as well as mobile engines used topower heavy duty industrial vehicles are powered by either direct drivediesel or diesel electric power trains frequently including a multiplehorse power turbo charged operation.

Accordingly, it is well recognized that distillate fuels, specificallydiesel, are used as the primary fuel source for such engines. Attemptsto maximize the operational efficiency, while maintaining reasonablesafety standards, have previously involved modified throttle controlfacilities. These attempts serve to diminish adverse effects of controlmechanisms which may be potentially harmful to the engine operation andmay also be at least generally uneconomical. Typical adverse effectsinclude increased fuel consumption and wear on operative components.Therefore, many diesel engines are expected to accommodate various typesof high capacity loads and provide maximum power for relativelysignificant periods of operation. As a result, many diesel engines arecommonly operated at maximum or near maximum capacity resulting in anattempted maximum power delivery from the engine and consequent highrates of diesel consumption. It is generally recognized that theprovision of a substantially rich fuel mixture in the cylinders of adiesel engine is necessary for providing maximum power when required.Such continued high capacity operation of the engine results not only inwear on the engine components, but also in high fuel consumption rates,lower operating efficiencies, more frequent oil changes and higher costsof operation.

Accordingly, there is a long recognized need for a fuel control systemspecifically intended for use with high capacity, variable or constantspeed compression ignition engines that would allow the use of moreefficient fueling methods using other commonly available fuel sources.Therefore, an improved fuel control system is proposed which isdeterminative of an effective and efficient operative fuel mixturecomprised of a combination of gaseous and distillate fuels. Morespecifically, gaseous fuels can comprise a natural gas or otherappropriate gaseous type fuels, wherein distillate fuel would typicallyinclude, but not be limited to diesel fuel.

Such a preferred and proposed fuel control system should be capable ofregulating the composition of the operative fuel mixture on which theengine operates to include 100% distillate fuel, when the operatingmode(s) thereof clearly indicate that the combination of gaseous anddistillate fuels is not advantageous. Further, such a proposed fuelcontrol system could have an included secondary function to act as ageneral safety system serving to monitor critical engine operatingparameters. As a result, control facilities associated with such apreferred fuel control system should allow for discrete, user definedcontrol and safety set points for various engine and/or fuel systemparameters.

In order to enhance efficient operation of an engine it is known to usea mass air flow sensor to determine the mass flow rate of air enteringan internal combustion engine. It is known that air changes its densityas it expands and contracts with temperature and pressure. As a result,it has been found that the determination of mass air flow is moreappropriate than volumetric flow sensors for accurately determining thequantity of intake air delivered to the combustion section of theengine.

In the proper operation of CI engines, other factors to be consideredinclude, but are not limited to, the occurrence of engine knocking.Knocking is a common occurrence in diesel engines where fuel is injectedinto highly compressed air at the end of the compression stroke. Thereis a short lag between the fuel being injected and combustion starting.Typically there is a quantity of fuel in the combustion chamber whichwill be ignited first in areas of greater oxygen density prior to thecombustion of the complete fuel charge. A sudden increase in pressureand temperature may cause what has been recognized as a distinctivediesel “knock” or “clatter”.

Yet another factor to be considered in the effective and efficientperformance of CI engines is “flammability limits”. Flammability limitsrefer to the fact that mixtures of gaseous fuel and air will only burnif the fuel concentration lies within well defined limits. The terms“flammability limits” and “explosive limits” are used interchangeablyand recognized flammability limits are typically determinedexperimentally. Maintaining a preferred combination of fuel and air inan explosive mixture is important in internal combustion enginesspecifically including, but not limited to, CI engines or dieselengines. In addition, it is important to maintain the air fuel mixturebelow “lower flammability limits” prior to the delivery of the air fuelmixture into the combustion chambers in order to avoid or restrictpre-ignition and resultant damage to the engine.

SUMMARY OF THE INVENTION

This invention is directed to a system and included apparatus,comprising technology that allows for the safe and efficient use of agaseous fuel such as, but not limited to, natural gas, in combinationwith a predetermined quantity of conventional distillate fuel, such asdiesel fuel. As a result, the composition of an “operative fuel mixture”used to power an associated engine will, dependent on the operatingmodes and/or operating characteristics thereof, be either a combinedmixture of gaseous fuel and distillate fuel or substantially entirelydistillate fuel, absent any contribution of gaseous fuel.

Moreover, the fuel control system of the present invention incorporates“real time” measurement capabilities specifically, but not exclusively,of each of the gaseous fuel and distillate fuel and the operative fuelmixture. More specifically, metering technology appropriate to each ofthe gaseous and distillate fuels will be used to establish thepercentage of gaseous fuel and diesel fuel contained in the compositionof the operative fuel mixture. Such appropriate metering will alsofacilitate the tracking of the overall gaseous fuel and diesel fuelconsumption.

Accordingly, the system of at least one preferred embodiment of thepresent invention includes both controlling and safety features,specifically adaptable for use with compression ignition engines (CI),of the type more fully described herein. It is to be noted that the term“operative fuel mixture” may, as set forth above, include a compositioncomposed of both gaseous fuel and distillate fuel present in varyingratios. However, for purposes of clarity, the term “operative fuelmixture” may also specifically refer to a composition comprisedsubstantially entirely of the distillate fuel. Therefore, and as setforth in greater detail hereinafter, the composition of the operativefuel mixture may best comprise both gaseous fuel and distillate fuel inpredetermined quantities, wherein the ratio of the gaseous anddistillate fuels may vary. It is again emphasized, that the term“gaseous fuel” is meant to include natural gas or other gaseous typefuels appropriate for engine operation. Similarly, the term “distillatefuel” refers primarily, but not exclusively, to a diesel fuel.

The system and assembly of the present invention allows operators ofstationary engines, including electric power generators and/or vehiclemounted engines, to substantially reduce costs, extend run time andimprove sustainability by substituting natural gas or other gaseous fuelfor a portion of the distillate fuel, such as diesel fuel inpredetermined ratios. As a result, safe use of a natural gas and othergaseous fuel is used in place of distillate fuel with the combinedratios of an “operative gas mixture” in the range of 50% to 70% of theengines total fuel requirement. Importantly, generators or otherstationary engines converted with the system and assembly of the presentinvention exhibit diesel like performance in such critical areas as loadacceptance, power output, stability and efficiency.

Additional advantages of the system and assembly of the presentinvention allow for the onsite conversion of stationary or mobileengines to natural gas and/or diesel fuel operation. The installationand/or conversion process utilizes components that are installedexternally of the engine/generator in a manner which does not requireany changes or modifications to the combustion section thereof. As such,OEM combustion section components including cylinders, pistons, fuelinjectors and/or cylinder heads remain the same. By retaining the OEMdiesel or distillate fuel system in its entirety, the operative andstructural features of the present invention maintains the enginescapability to operate solely on diesel fuel when such is needed based onthe operational modes or operating characteristics of the engine.

Moreover, the present invention utilizes “pipe-line supplied gaseousfuel” at a positive pressure, generally in the range of 3 psi to 7 psi.Accordingly, gaseous fuel is added to the intake air of the combustionsection of the engine, at a positive pressure, utilizing one or moreunique mixing assemblies. In more specific terms, each of the one ormore mixing assemblies includes an electronically controlled throttlebody integrated with a fixed geometry, low restriction air gas mixture.In terms of the integrated features of the throttle body andcorresponding air gas mixer, the air gas mixer comprises a housingwherein the throttle body is fixedly mounted on or connected directly tothe housing of the corresponding air gas mixer, such as on the exteriorthereof. In addition, at least a portion of the housing of the air gasmixer is disposed in and thereby may at least partially define a path oftravel or flow line of intake air to the combustion section of theengine. Moreover, a dispensing nozzle is disposed within the interior ofthe housing in direct communication and/or aligned relation within theflow path of the intake air. Further, a delivery conduit is disposed onthe interior of the housing of the air gas mixer in interconnecting,gaseous fuel delivering relation between the throttle body and thedispensing nozzle.

As indicated, the supply of gaseous fuel is maintained at a positivepressure and delivered from the fuel supply to the throttle body andeventually from the throttle body to the corresponding, integrated airgas mixer at such positive pressure. Therefore, the gaseous fuel supply,throttle body and integrated air gas mixer are cooperatively structuredand collectively operative to deliver gaseous fuel in appropriate,variable quantities and under a positive pressure to the intake air ofthe combustion section of the engine. This may differ from conventionalfuel systems, wherein fuel is not maintained under a positive pressureor “pushed” from a fuel delivery assembly into the flow path of intakeair. Moreover, one advantageous feature of the positive pressuredelivery of the gaseous fuel of the present invention comprises theability to “predict” and/or more precisely control the quantity ofgaseous fuel being delivered to the flow of intake air and to thecombustion section of the engine. As a result the maximum amount ofgaseous fuel, within predetermined limits or parameters, may be added tothe gaseous and distillate fuel mixture of the operative fuelcomposition and thereby assure efficient operation of the engine withoutconsuming an excessive amount of distillate fuel. Factors which maylimit the delivery of the maximum quantity of gaseous fuel, as set forthabove may include, but are not limited to, the occurrence of “knocking”in the engine, maintaining appropriate lower flammability limits, etc.

Further direct mounting or connection of the throttle body to theintegrated air gas mixer provides an additional safety feature. Morespecifically, due to such an integrated structure, there will not be acollection of gaseous fuel in a connecting conduit or line, betweenthrottle body and air gas mixer and/or intake air, which may exist inconventional fuel systems. Therefore, unlike conventional fuel deliveryconnections, the gaseous fuel of the present invention may be “pushed”under the aforementioned positive pressure from the throttle bodydirectly into the air gas mixer.

Dependent on the structural and operative features of the engine and/orgenerator with which the system and included structure is utilized, aturbo charger may be disposed within one or more intake air flow pathsto the combustion chamber. When one or more turbochargers are soutilized and installed, the integrated throttle body and air gas mixerare disposed in fluid communication with the corresponding flow pathupstream of the turbocharger. In yet another preferred embodiment of thesystem and assembly of the present invention a plurality of mixingassemblies are utilized, wherein each mixing assembly comprises anintegrated throttle body and air gas mixer. As set forth above, thestructural integration of each of the throttle body and correspondingair gas mixer comprises the air gas mixer including a housing disposedat least partially within and thereby at least partially defining theintake air flow path to the combustion section of the engine. Further,each throttle body will be fixedly mounted on or directly connected tothe corresponding, integrated air gas mixer, such as on the housingthereof, to at least partially define the integrated structure thereof.The result of this integrated structure will be the advantages andenhanced operative features, as set forth above.

As also indicated, each of the throttle bodies are independentlyoperable based on monitored data determined by the ECU. As a result,each of a plurality of integrated throttle bodies/air gas mixers mayprovide a different and variable gaseous fuel flow to a different intakeair flow path and corresponding combustion cylinder of the combustionsection of the engine. Therefore, each combustion cylinder associatedwith the engine/generator with which the system of the present inventionis utilized, may receive a gaseous fuel and distillate fuel mixturewhich differs from one or more of the other cylinders, depending uponthe operating characteristics of the engine. This allows for evengreater efficiency in regulating output of the engine based on operatingcharacteristics of the engine, as detected by the monitoringcapabilities of the ECU. Such engine operating characteristics include,but are not limited to, fuel rates, exhaust gas temperatures, vibrationslevels, manifold air temperatures, mass air flow, gas pressures, enginecoolant temperature, engine RPM, compressor inlet pressures and/ormanifold air pressures. Operational enhancement and versatility of theECU is structured to sample each data input up to 50 times per secondthereby insuring rapid detection and collection of anomalies.

Yet another preferred embodiment of the present invention is directed toa fuel control system operative to establish gaseous fuel input for acompression ignition (CI) or diesel engine which is powered by avariable mixture of gaseous and distillate fuels dependent, at least inpart, on the operating characteristics or parameters of the CI engine.Moreover, this additional preferred embodiment includes an electroniccontrol module (ECU), of the type generally described above and ingreater detail herein. As such, the ECU is operative to determine and/orregulate a concentration of gaseous fuel added into the intake air whichis then directed to the combustion section of the CI engine. In order tofacilitate proper and more efficient operation of the CI engine, a massair flow measuring assembly comprising at least one mass air flow (MAF)sensor. The at least one MAF sensor is disposed in monitoring relationto the flow of intake air and along the flow path thereof upstream of athrottle assembly, also to be described in greater detail herein after.

The at least one MAF sensor is operatively connected to the ECU andcooperatively structured therewith to transfer appropriate,predetermined data and/or data signals thereto. The data delivered fromthe MAF sensor to the ECU is indicative of mass flow rate of the intakeair passing along the path of intake air flow to the combustion sectionof the engine. The at least one MAF sensor is preferred over other knownor conventional volumetric flow sensors for determining the quantity ofintake air due to its greater accuracy and/or dependency in certainapplications and at least partially dependent on the use of the enginewith which the one MAF sensor is combined. As will also be described ingreater detail, this additional preferred embodiment defines the massair flow measuring assembly as including the one MAF sensor comprising a“hot wire” MAF sensor. As utilized and applied, the hot-wire mass airflow sensor functions by heating a wire, which is suspended in theengines intake air, with an electric current. The wire's electricalresistance increases when the wire temperature increases. This in turnlimits the electrical current flowing through the circuit. When intakeair flows past the wire, the wire cools thereby decreasing itsresistance, which in turn allows more current to flow through thecircuit. The current flow through the circuit increases the wire'stemperature until the resistance reaches equilibrium.

Accordingly, it may be determined that the operative current required tomaintain the wires temperature is proportional to the “mass air flow”over the heated wire. Moreover, the integrated electronic circuitassociated with the hot-wire MAF sensor converts the measurement ofcurrent to a voltage signal which is then sent to the ECU. The voltagesignal or data signal, as used herein, is thereby indicative of the massair flow rate of the intake air which in turn will be determinative,within certain operational parameters of the engine, of the amount ofgaseous fuel which is added to the intake air flow directed to thecombustion section of the CI engine. Further with regard to thesestructural and operative features of the hot-wire MAF sensor, if airdensity increases due to pressure increase or temperature increase ortemperature drop while the air volume remains constant, the denser airwill remove more heat from the heated wire indicating a higher mass airflow. Therefore, unlike other related sensors the hot-wire MAF sensorresponds directly to air density. As a result, the hot-wire sensorrepresents a distinctive and more efficient operative component of thispreferred embodiment of the fuel control system as it is better suitedto support the combustion process of a CI engine which operates on avariable mixture of gaseous and distillate fuels.

Further, it is to be noted that the aforementioned predeterminedoperating parameters of this preferred embodiment include, but are notlimited to, a maximum gaseous fuel input into the intake air flow of4.5% by volume of the quantity of intake air based on the determinationof by the mass flow rate of the intake air. Moreover, the 4.5% ofgaseous fuel relative to intake air is also sufficient to maintain lowerflammability limits of the air mass and gaseous fuel mixture prior toentering into the combustion chambers of the CI engine.

Additional predetermined operating parameters also include therestriction, reduction or prevention of engine knocking. Morespecifically, this preferred embodiment of the fuel control system ofthe present invention includes an engine knock sensor operativelyconnected to the ECU. Accordingly, when engine knocking is detected thepredetermined operating parameters dictate that the input of gaseousfuel into the intake air flow is reduced to an amount which serves toeliminate or at a minimum significantly restrict the occurrence ofengine knocking so as to prevent damage to the engine.

As also explained in greater detail, the “throttle assembly” used in thestructure and operation of this embodiment of the fuel control systempreferably comprises the “throttle body” associated with theaforementioned mixing assembly. Accordingly, the throttle assemblycomprises and/or is at least partially defined by the structurallyintegrated throttle body and air gas mixer. Moreover, the integratedthrottle body and air gas mixer is disposed and structured to disposethe throttle body in fluid communication with a positively pressuredgaseous fuel supply. As a result, gaseous fuel is “pushed” under apositive pressure, to the integrated throttle body and air gas mixer andthere through to the intake air flow, being directed to the combustionsection of the CI engine.

Due to the fact that the gaseous fuel is delivered under a positivepressure from the gaseous fuel supply it can be more efficientlyregulated by effectively “pushing” the gaseous fuel through the throttlebody into the air gas mixer and therefrom directly into the intake airflow in specified quantities and/or volumes to accommodate delivery ofgaseous fuel in the amounts no greater than the 4.5% by volume of intakeair and/or controlled, lesser amounts to restrict engine knocking andother unwanted operating features associated with the CI engine.

These and other objects, features and advantages of the presentinvention will become clearer when the drawings as well as the detaileddescription are taken into consideration.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature of the present invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings in which:

FIG. 1 is a perspective view of one preferred embodiment of the systemand assembly of the present invention wherein a mixing assemblycomprising an integrated throttle body and air gas mixer are connectedto an intake air flow path being delivered to a combustion section of anengine/generator with which the mixing assembly is utilized.

FIG. 2 is a schematic representation of the embodiment of FIG. 1.

FIG. 3 is a schematic representation of yet another preferred embodimentof the system of the present invention comprising a plurality of mixingassemblies of the type represented in FIGS. 1, 4 and 5.

FIG. 4 is a perspective detailed view of an integrated throttle body andair gas mixer defining one of a possible plurality of mixing assembliesof the type represented in FIG. 1.

FIG. 5 is a rear perspective detailed view of the embodiment of FIG. 4.

FIG. 6 is a schematic representation of yet another preferred embodimentof the fuel control system of the present invention.

Like reference numerals refer to like parts throughout the several viewsof the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As schematically represented in the accompanying Figures, the presentinvention is directed to a control system and included structureoperative to establish a coordinated operative fuel mixture of combinedgaseous fuel and distillate fuel. The ratio of gaseous fuel todistillate fuel will vary dependent on the operating characteristics ofan engine which incorporates the structural and operative features ofthe system of the present invention. In particular, the control systemof the present invention is specifically, but not exclusively, adaptablefor use with stationary compression ignition (CI) engines or generators,which may or may not include turbo-charging capabilities.

With primary references to FIGS. 1-3, the system of the presentinvention comprises an electronic control unit 12 operative to monitorat least predetermined engine data associated with and indicative of theoperating characteristics of the engine with which the system isutilized. It is emphasized that FIGS. 2 and 3 are schematicrepresentations intended to provide a detailed description of thestructural and operative characteristics of the system of the presentinvention. As such, the electronic control unit (ECU) 12 includes aplurality of data channels 14 for the monitoring of intended,predetermined or critical parameters such as, but not necessarilylimited to fuel rates, exhaust gas temperatures, operation levels,manifold air temperatures, mass air flow, gas pressure, engine coolant,engine RPM, compressor inlet pressures and manifold air pressures, etc.

In addition, one feature of the system of the present invention is theincorporation of at least one mixing assembly generally indicated as 16.As also schematically represented in FIG. 3, yet another preferredembodiment of the system of the present invention incorporates the useof a plurality of such mixing assemblies 16 as will be described ingreater detail hereinafter. Accordingly, each mixing assembly 16comprises an integrated throttle body 18 and air gas mixer 20. Each ofthe one or more throttle bodies 18 is connected in fluid communicationwith a gaseous fuel supply 22. Moreover, each of the air gas mixers 20,being structurally integrated with a corresponding one of throttlebodies 18, is disposed in direct fluid communication with a flow path 22of intake air 22′, wherein the flow path or flow line 22 may be an OEMportion of the engine, as represented in FIG. 1, so as to deliver intakeair 22′ to a combustion section 24 of the engine.

With primary reference to FIGS. 1, 4 and 5 each of the one or moremixing assemblies 16 is defined by the structurally integrated throttlebody 18 and air gas mixer 20. As such, the air gas mixer 20 includes ahousing 26 having an interior 28 which at least partially defines acorresponding one of the flow paths 22 of the inlet air 22′ beingdelivered to the combustion section 24. As clearly represented in FIG.1, the housing 26 of the air gas mixer 20 may be installed directlyin-line with the corresponding OEM air intake flow path 22, by anyappropriate fluid seal connectors, as at 25, Such installation therebyfacilitates the interior 28 of the housing 26 defining at least aportion of the flow path 22 of the intake air 22′.

Additional structural features of the air mixer 20 include a dispensingnozzle 30 represented in FIGS. 3 and 4. The dispensing nozzle 30includes an aerodynamically shaped head 31 formed on one end of thenozzle 30. A plurality of dispensing nozzle ports 32, represented inFIG. 4, are disposed downstream of the head 31 and are structured todeliver or dispense the gaseous fuel, received from the corresponding,integrated air mixer 20, directly into the intake air 22′ travellingalong the intake air flow path 22 as set forth above. At least one, butpreferably a plurality of interconnecting segments or vanes 34, aredisposed and structured to facilitate the substantially aligned,supported disposition of the dispensing nozzles 30 into the flow path 22of intake air 22′. Further, each of the connecting vanes 38 may beconfigured and dimensioned to not adversely disrupt air flow 22′ andfurther facilitate proper mixing of the gaseous fuel into the flow ofintake air 22′. A delivery conduit 40 is also disposed on the interiorof the housing 26 and serves to provide a direct fluid flow connectionof gaseous fuel from the throttle housing 18 into the delivery nozzle 30of the corresponding, integrated air gas mixer 20.

In at least one preferred embodiment, the structural integration of thethrottle body 18 and air gas mixer 20 comprises the mounting and/ordirect fixed connection of the throttle body 18 on the exterior of thehousing 26. Therefore, the delivery conduit 40 is in direct fluidcommunication between the nozzle 30 and the outlet fuel outlet (notshown) from the throttle body 18. Due to such an integrated structure,there will not be a collection of gaseous fuel in a connecting conduitor line, between throttle body and air gas mixer and/or intake air,which may exist in conventional fuel systems. Therefore, unlikeconventional fuel delivery connections, the gaseous fuel of the presentinvention may be “pushed” under positive pressure from the throttle body18 directly into the air gas mixer 20.

More specifically, and as indicated herein, the gaseous fuel supply 21stores, maintains and dispenses the gaseous fuel under a positivepressure to the throttle body 18. As a result, there will be a positivepressure flow of gaseous fuel, through the delivery conduit 40, into thedispensing nozzle 30. Due to this positively pressurized fuel delivery,there will be no collection of gaseous fuel between the throttle body 18and the dispensing nozzle 30 of the air gas mixer 20 as may be known inconventional fuel systems as at least generally set forth above.Therefore, the supply of gaseous fuel is maintained at a positivepressure and delivered from the fuel supply 21 to the throttle body 18and eventually from the throttle body 18 to the corresponding,integrated air gas mixer 20 at such positive pressure. Accordingly, thegaseous fuel supply 21, throttle body 18 and integrated air gas mixer 20are cooperatively structured and collectively operative to delivergaseous fuel in appropriate, variable quantities and under a positivepressure to the intake air 22′ of the combustion section 24 of theengine.

In the embodiments of FIGS. 1, 4 and 5, the throttle body 18 iselectrically powered and as such includes an electrical socket or otherappropriate connection 44. Further, the delivery of gaseous fuel fromthe fuel supply 21, under pressure, to the throttle body 18 isaccomplished by interconnection of an appropriate conduit or line to athrottle body inlet 46.

With primary reference to FIG. 3 in combination with the structuraldetails represented in FIGS. 1, 4 and 5, an additional preferredembodiment of the system comprises the electronic control unitstructured to monitor predetermined engine data by virtue of at leastone but more practically a plurality of data input and input channels14. As indicated, the monitored engine data is determinative of enginefuel requirements and will ultimately determine the appropriate and/ormost efficient ratio between the distillate fuel and gaseous fueldefining the aforementioned operative fuel mixture being delivered tothe combustion section 24 and/or the individual combustion cylinders 24′defining the combustion section 24. As with the embodiment of FIG. 2,additional preferred embodiment includes a pressurized gaseous fuelsupply 21 structured to retain and dispense the gaseous fuel under apositive pressure preferably, but not necessarily, of generally about 3psi to 7 psi. As also emphasized above, each of the one or more mixingassemblies 16 are structured to independently establish a predeterminedcoordinated mixture and/or ratio of gaseous and distillate fuels, whichin turn define the operative fuel mixture for each combustion section 24and more specifically for each of the combustion chambers 24′. Asindicated, the supply of gaseous fuel is maintained at a positivepressure and delivered from the fuel supply 21 to the throttle body 18and eventually from the throttle body 18 to the corresponding,integrated air gas mixer 20 at such positive pressure. Therefore, thegaseous fuel supply, throttle body 18 and integrated air gas mixer 20are cooperatively structured and collectively operative to delivergaseous fuel in appropriate, variable quantities and under a positivepressure to the intake air of the combustion section 24 of the engine.

Therefore, in the additional preferred embodiment of FIG. 3, a pluralityof mixing assemblies 16 each include an integrated throttle body 18 andair gas mixer 20. As a result, each of the various cylinders 24′ of thecombustion section 24 may have a different, variable ratio of gaseousand distillate fuels delivered thereto. Accordingly, an effectivelydifferent operative fuel mixture may be consumed in the differentcombustion chambers 24′. It is also emphasized that the ECU 12 and theone or more input data channels 14 are structured to continuously andrepetitively monitor the predetermined engine data which in turn isdeterminative of the specific and/or range or ratios of distillate andgaseous fuels present in the mixture of the operative fuel mixture beingdelivered to each of the chambers 24′.

Accordingly, each of the plurality of mixing assemblies 16 comprises theintegrated throttle body and air gas mixer 18 and 20 respectively.Further, each of the throttle bodies 18 is independently connected ingaseous fuel receiving relation to a common and/or separate fuel supply21. As also represented, each of the air gas mixers 20 is disposed influid communication with a different flow path 22 and the intake air 22′associated therewith. Further, the integrated structure of each of themixing assemblies 16 include a throttle body 18 fixedly mounted onand/or connected to an exterior of a corresponding housing 26 of theassociated, integrated air gas mixer 20. Similarly, each of the air gasmixers 20 includes a delivery nozzle 30 receiving gaseous fuel from acorresponding, integrated throttle body 18 through a delivery conduit40. As such, each of the delivery conduits 40 is disposed within theinterior 28 the housing 26 of corresponding ones of the air gas mixers20.

With further regard to both FIGS. 2 and 3, dependent on the intendedoperation and structure of the engine with which the system of thepresent invention is utilized, a turbocharger 50 may be disposed withinor along the flow path 22 of intake air 22′ so as to further process theintake air 22′ prior to being delivered to the combustion section 24and/or individual cylinders 24′. In the embodiment of FIG. 2, a singleturbocharger 50 is located between the mixing assembly 16 and thecombustion section 24, such that the mixing assembly 16, including theintegrated throttle body 18 and air gas mixer 20 is upstream along theflow path 22 of intake air 22′ being delivered to the combustion section24.

Yet another preferred embodiment of the fuel control system of thepresent invention is schematically represented in FIG. 6. Many of thestructural and operative features of the embodiment of FIG. 6 aresubstantially equivalent to the embodiments of FIGS. 1 through 5.Accordingly the additional preferred embodiment, as represented in FIG.6 comprises the ECU 12 operative to monitor at least predeterminedengine data associated with and indicative of the operatingcharacteristics of the IC engine. The ECU comprises a plurality of datachannels 14 for the monitoring of intended, predetermined operatingparameters of the engine, which may be critical to the safety and/orappropriate fuel mixture. Such predetermined operating parametersinclude, but are not necessarily limited to, fuel rates, exhaust gastemperatures, operation levels, manifold air temperature, mass air flow,gas pressure, engine coolant, engine RPM, compressor inlet pressures andmanifold air pressures, etc.

Further, the preferred embodiment of FIG. 6 also includes a throttleassembly which is embodied in the aforementioned and described mixingassembly, which is generally represented in FIG. 6, as 116. As such, themixing assembly 116 comprises a structurally integrated throttle body 18and an air gas mixer 20 connected in fluid communication with a gaseousfuel supply 21 maintained under a positive pressure. Therefore, gaseousfuel delivered from the fuel supply 21 is effectively “pushed” under theaforementioned positive pressure to the throttle body 18. The positivedelivery of the gaseous fuel to the throttle body 18 and there from tothe air gas mixer 20 thereby allows a “predictive” amount of gaseousfuel being delivered to the intake air 22′.

In more specific terms and again with primary referenced to FIG. 6, theECU 12 is operative to determine and/or regulate the concentration ofgaseous fuel within the intake air flow 22, 22′ being delivered to acombustion section 24 of the CI engine. In order to affect a moreprecise quantity of gaseous fuel utilized to power the combustionsection 24, a mass air flow measuring assembly 60 is inserted in fluidcommunication with the path of inlet air flow 22 and in direct fluidcommunication with the intake air 22′. Moreover, the mass air flowmeasuring assembly 60 preferably includes at least one mass air flowsensor 62 operatively connected to the ECU 12 so as to provide signalsdetermination of the mass air flow rate of the intake air 22′ passingalong the intake flow path 22. In turn the ECU 12 is operativelyconnected to the mixing assembly 116 including throttle assemblyincluding the integrated throttle body and the air gas mixer 18 and 20respectively. As a result, gaseous fuel delivered under pressure fromthe fuel supply 21, will be effectively “pushed” in adequate quantitiesto sufficiently and safely power the combustion section 24. In addition,the throttle body 18 is cooperatively structured with the ECU 12 andoperative therewith to establish a sufficient concentration and/orquantity of gaseous fuel being delivered to the intake air 22′ to complywith proper operation of the CI engine in accord with predeterminedoperating parameters of the CI engine. As also indicated the conditionof state of the predetermined operating parameters are determined by theECU 12 over data channels 14.

Accordingly, in this preferred embodiment of the present invention, theaforementioned operating parameters specifically include, but are notlimited to, a maximum gaseous fuel input into the intake air of 4.5% byvolume of the quantity of intake air and/or mass flow rate thereof.Moreover, the operating parameters can also be at least partiallydefined by a control of the quantity of gaseous fuel into the intake air22′ which is sufficiently less to eliminate or restrict the occurrenceof engine knocking. Therefore, the additional preferred embodiment ofFIG. 6 may also include an engine knocking sensor 64 disposed andstructured to facilitate the detection of engine knocking. Further theengine knocking sensor 64 is connected and/or operatively structuredwith the ECU 12 to facilitate the determination by the ECU 12 thatengine knocking is or has occurred. In turn the ECU 12 is operativelyconnected to the throttle assembly or throttle body 18 so as to regulateand more specifically diminish the quantity of gaseous fuel beingdelivered into the intake air 22′ through the aforementioned integratedgas mixer 20. As such, the lesser quantity of gaseous fuel, below themaximum of 4.5% by volume of intake air is sufficiently reduced torestrict the engine knocking.

Since many modifications, variations and changes in detail can be madeto the described preferred embodiment of the invention, it is intendedthat all matters in the foregoing description and shown in theaccompanying drawings be interpreted as illustrative and not in alimiting sense. Thus, the scope of the invention should be determined bythe appended claims and their legal equivalents.

Now that the invention has been described,

What is claimed is:
 1. A control system for establishing gaseous fuelinput for a compression ignition engine operative on a variable mixtureof gaseous and distillate fuels, said control system comprising: anelectronic control module (ECU) operative to regulate a concentration ofgaseous fuel within an intake air flow to a combustion section of the CIengine, a mass air flow measuring assembly comprising at least one massair flow (MAF) sensor disposed in monitoring relation to the intake airflow, said one MAF sensor operatively connected to said ECU andstructured to transfer data signals to said ECU indicative of a massflow rate of the intake air flow, a throttle assembly structured todeliver variable quantities of gaseous fuel to the intake air flowdependent at least on the mass flow rate of intake air, and saidthrottle assembly cooperatively structured with said ECU and operativetherewith to establish a sufficient concentration of gaseous fueldelivered to the intake air flow to comply with predetermined operatingparameters of the CI engine.
 2. A control system as recited in claim 1wherein said predetermined operating parameters comprise a maximumgaseous fuel input of 4.5% by volume of the mass flow rate of intakeair.
 3. A control system as recited in claim 2 wherein saidpredetermined operating parameters further comprise a sufficient inputof gaseous fuel to restrict the occurrence of engine knocking.
 4. Acontrol system as recited in claim 1 wherein said predeterminedoperating parameters comprise an input of a sufficiently reducedquantity of gaseous fuel to restrict the occurrence of engine knocking.5. A control system as recited in claim 4 further comprising a knocksensor assembly operatively disposed relative to the combustion sectionand structured to determine an occurrence of engine knock therein.
 6. Acontrol system as recited in claim 5 wherein said knock sensor assemblyis operatively connected to said ECU and structured to signal said ECUof an occurrence of engine knock in the combustion section.
 7. A controlsystem as recited in claim 6 wherein said ECU is cooperativelystructured with said throttle assembly to regulate delivery of gaseousfuel to the intake air based on the determination of engine knock bysaid knock sensor assembly.
 8. A control system as recited in claim 6wherein said ECU is cooperatively structured with said throttle assemblyto deliver a diminished quantity of gaseous fuel to the intake air flowupon a determination of engine knock by said knock sensor assembly.
 9. Acontrol system as recited in claim 8 wherein said diminished quantity ofgaseous fuel comprises an amount sufficiently less than 4.5% by volumeof the mass flow rate of intake air to restrict engine knock in thecombustion section.
 10. A control system as recited in claim 9 whereinsaid predetermined operating parameters comprise a maximum gaseous fuelinput of 4.5% by volume of the mass flow rate of intake air.
 11. Acontrol system as recited in claim 1 wherein said one MAF sensorcomprises a hot-wire MAF sensor.
 12. A control system as recited inclaim 1 further comprising a gaseous fuel supply structured to retainand deliver the gaseous fuel under a positive pressure; said throttleassembly and said gaseous fuel supply being cooperatively structured todirect the variable gaseous fuel flow from the throttle assembly to theintake air at a positive pressure.
 13. A control system as recited inclaim 12 wherein said predetermined operating parameters comprise amaximum gaseous fuel input of 4.5% by volume of the mass flow rate ofintake air.
 14. A control system as recited in claim 1 further includingat least one mixing assembly comprising an air gas mixer structurallyintegrated with said throttle assembly, said throttle assembly disposedin fluid communication with said gaseous fuel supply and said air gasmixer disposed in gaseous fuel delivering relation with the intake airflow to the combustion section.
 15. A control system as recited in claim14 further comprising a gaseous fuel supply structured to retain anddeliver the gaseous fuel under a positive pressure; said throttleassembly structured to direct a variable gaseous fuel flow under saidpositive pressure directly to said integrated air gas mixer there fromto the intake air flow.
 16. A control system for establishing gaseousfuel input for a compression ignition engine operative on a variablemixture of gaseous and distillate fuels, said control system comprising:an electronic control module (ECU) operative to regulate a concentrationof gaseous fuel within intake air flow to a combustion section of the CIengine, a mass air flow measuring assembly comprising at least one massair flow (MAF) sensor disposed in monitoring relation to the intake airflow, said one MAF sensor operatively connected to said ECU andstructured to transfer data signals to said ECU indicative of a massflow rate of the intake air flow, a gaseous fuel supply structured toretain and dispense the gaseous fuel under a positive pressure, at leastone mixing assembly comprising a structurally integrated throttle bodyand air gas mixer, said throttle body structured to direct a variablegaseous fuel flow under the positive pressure directly to saidintegrated air gas mixer and there from to the intake air, and saidthrottle body cooperatively structured with said ECU and operativetherewith to establish a sufficient concentration of gaseous fueldelivered to said integrated air gas mixer and the intake air flow tocomply with predetermined operating parameters of the CI engine.
 17. Acontrol system as recited in claim 16 wherein said predeterminedoperating parameters further comprise an input of a quantity of gaseousfuel sufficient to restrict the occurrence of engine knock.
 18. Acontrol system as recited in claim 17 further comprising a knock sensorassembly operatively disposed relative to the combustion section andstructured to determine an occurrence of engine knock therein.
 19. Acontrol system as recited in claim 18 wherein said predeterminedoperating parameters comprise a maximum gaseous fuel input of 4.5% byvolume of the mass flow rate of intake air.
 20. A control system asrecited in claim 19 wherein said ECU is cooperatively structured withsaid throttle body to deliver a diminished quantity of gaseous fuel tothe intake air flow upon a determination of engine knock by said knocksensor assembly.
 21. A control system as recited in claim 20 whereinsaid diminished quantity of gaseous fuel comprises an amountsufficiently less than 4.5% by volume of the mass flow rate of intakeair to restrict engine knock in the combustion section.
 22. A controlsystem as recited in claim 1 wherein said one MAF sensor comprises ahot-wire MAF sensor.